The bishop posted his open letter on social media, with the post being viewed more than two million times and attracting 56,000 likes on X.

Parts of the plea details Britain’s history with the Christian faith, saying: “It has defined her.”

The King has been urged to take action

It claims that faith has been “deliberately eroded”, adding: “There is a growing hostility toward the faith.”

It continues: “Christian belief is mocked in the public square. Christian morality is dismissed as intolerance.

“Christian institutions are pressured to surrender doctrine in order to conform to the ideology of the age.”

The bishop has called on the King “to stand as a guardian of the Christian inheritance of the nation”.

The message addressed to the monarch warned that Christianity has been ‘deliberately eroded’

Addressing the King, the bishop said: “I write to say this, Your Majesty: The Christian character of this nation is under profound and accelerating assault.

“If the Crown does not stand visibly and courageously in defence of that inheritance, history will record that the guardians of Britain’s institutions watched in silence as the foundations were removed.”

Bishop Ceirion Dewar warned Charles that the country “now stands at a crossroads that few monarchs in modern history have faced”.

He said: “You may preside over the quiet dissolution of Britain’s Christian identity. Or you may rise to the ancient responsibility entrusted to the Crown and speak with clarity about the faith that built this kingdom.

The Bishop told the King the country ‘now stands at a crossroads that few monarchs in modern history have face’

“The first path requires little courage. The second will require a great deal. But it is the path that history honours.”

He called on the King to show “leadership” and act upon the title: “Defender of the Faith.”

The bishop’s message continued: “[Your Majesty’s subjects] are asking that the Crown hear the growing cry of anguish from Christians across this land who feel that the spiritual inheritance of their nation is being surrendered without resistance.

“And they are asking whether the Crown will stand with them.”

The Bishop called on the King to show ‘leadership’

Bishop Ceirion Dewar urged the King to act, feeling that if Christianity is “cast aside, the nation will discover – too late – that it has severed itself from the very roots that sustained it”.

His message concluded: “Your Majesty, to many the Crown is a symbol of authority. But before God it is also a symbol of stewardship. And stewardship carries with it the duty to defend what has been entrusted.

“May Almighty God grant Your Majesty the wisdom to discern this hour, and the courage to fulfil the sacred duty entrusted to the Crown.”

GB News has contacted Buckingham Palace for a response to the open letter.